test_driven_development

Test-Driven Development (TDD)

Business benefits of TDD:
Deliver more value, faster
Always ship working software
Adapt to change quickly

Code benefits of TDD:
Readable specs and code
Clean public interfaces
Decoupled modules

Process benefits of TDD:
Regression safety net
Fearless refactoring
Team trust

At a high level, how to test is very simple:
Write test first.
Red-Green-Refactor cycle.
For more specifics, we recommend our Test-Driven Rails workshop. It goes into incredible detail about the TDD workflow specifically for Ruby on Rails developers.